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Патент USA US3036879

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May 29, 1962
c. v. CROCKETT
3,036,869
BRAKE ACTUATING SYSTEM
Filed Sept. 9, 1957
To Other Wheels of
Hydraulic Broke-‘System
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7
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Hf? 7
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3 14
63
From Cooler
INVENTOR.
47
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Clarence V Croc/ref/
BY
61%.
nited‘ States Patent 0
1
31,036,869
1
Patented May 29, 1962
2
lated according to the maximum pressure deliverable by
3,036,869
the coolant circulating pump to obtain a controlled and
Clarence V. Crockett, Pontiac, Mich, assignor to Gen
predetermined liquid pressure to be applied to the wheel
cylinder of the brakes. To regulate the maximum pres
BRAKE ACTUATING SYSTEM
eral Motors Corporation, Detroit, Mich, a corporation
Filed Sept. 9, 1957, Ser. No. 682,745
sure to be applied to the wheel cylinders of the brakes by
the coolant circulating pump, pressure actuated valve
4 Claims. (Cl. 303-2)
means are provided to provide for a release of coolant
of Delaware
,
fluid from the output side of the pump into the brake
This invention relates to an actuating system for the
when the maximum pressure of the control valve setting
brakes of a wheeled vehicle, and particularly to a system 10 is reached, this occurring during a time when the man
for actuating the friction brakes of a motor vehicle.
ually operated mechanism is effecting a brake operation
In this invention the brakes of the motor vehicle are of
with power assist from the coolant pump.
the multiple disk type wherein engagement of the disks
The brake system is also arranged to utilize the hy
effect a braking action for the vehicle, some of the disks
draulic power assist from the coolant pump at any time a
being rotatable with the axles of the vehicle and other of 15 brake line should break somewhere between the brake
the disks being stationary. The disk assembly, comprising
and the master cylinder. A check valve is provided in the
alternate stationary and rotatable disks is adapted to be
brake line between the master cylinder and the brake
actuated by a hydraulically operated wheel cylinder that
which closes when the pressure in the brake line is below
causes engagement of the disks for a brake operation.
the pressure in the discharge side of the coolant pump
The wheel cylinder is connected with a master cylinder 20 and thereby prevent loss of liquid from the coolant pump '
that is operated by the brake pedal of the vehicle to dis—
that is being delivered to the wheel cylinder for power
place ?uid from the master cylinder into the wheel cyl
inder to effect the braking operation.
.
assist of the manually operated mechanism.
Further objects and advantages of the present invention
The heat ‘of friction created between the rotating and
will be apparent. from the following description, refer
stationary disks of the brake is removed by circulation of 25 ence being had to the accompanying drawings wherein a
a cooling liquid between the disks, or through the brake,
preferred form of the invention is clearly shown.
a ?uid pump being driven by the wheel axle to effect the
In this invention the brake mechanism is illustrated as
circulation of cooling liquid through the brake and thence
being applied to the rear axle of a motor vehicle. Prefer
through a heat transfer device or cooler.
ably both rear wheel brakes are constructed and arranged
The pump for circulating the cooling liquid is prefer~ 30' as illustrated in the drawing with a positive displacement
ably located within the rear wheel brakes ‘of a vehicle and
pump such as a gear or a vane type being provided to
the pumps are adapted to circulate the cooling liquid
effect circulation of the cooling liquid through th'ebrake
through the rear wheel brakes and also through the front
and thence through a cooler or heat exchange device.
wheel brakes of the vehicle.
The
front wheel brakes are similar to the rear wheel
It is conventional to provide a mechanically operated 35 brakes except that the coolant pump can be eliminated
parking or emergency brake on at least the rear wheels
of a motor Vehicle so that the wheel brakes having the
mechanically operated parking brakes can be set to retain
the vehicle in a stationary position. The manually oper
ated mechanical mechanism is adapted to actuate the disk
assembly to effect engagement of the disks and thereby
provide for a parking brake, or an emergency manual op
eration of the disk assembly to stop the vehicle.
In this invention the liquid under pressure circulated
from the front wheel brake with the pumps‘ in the rear
wheel brakes providing for circulation of coolant through
the front wheel brakes.
In the drawing, the brake 10 is supported upon the axle
11. The outboard end of the axle 11 has a ?ange 12
adapted to support a wheel. The axle 11 is contained
within an axle housing 13 that has a ?ange 14 that sup
ports the brake housing 15, the axle housing 13, the ?ange,
and
brake housing 15 being stationary components.
by the pump for cooling the brake is utilized to provide 45 Grease seals 16 are provided between the axle 11 and
for a power assist of the manually operated mechanical
parking brake mechanism to thereby reduce the effort re-'
quired to set the parking brake and to provide an hy
draulic actuation of the disk brake assembly to effect pri
mary braking with the mechanical parking brake mecha
nism providing a follow-up mechanism to the hydraulic
mechanism to retain the disk brake in the position set by
the cooperation of the hydraulic and mechanical mecha
the axle housing 13 to prevent interchange of oil or grease
between the brake and the differential of the vehicle.
The disk brake consists of a brake disk carrier 17' that
is supported upon the axle 11 by means of the spline 18.
The carrier has the radial wall 19‘ that terminatesv in the
annulus 28 that has a plurality of teeth or splines '21
which in turn supports one or more brake disks 22. The
brake disks 22 thus rotate with the axle 11. The axle
11 is journaled in the brake housing 10 by means of an
55
The foregoing operation of using the pressure ?uid from
anti-friction bearing 23, an oil seal 24 preventing loss of
the cooling pump is initiated and rendered effective by op
coolant oil from within the brake housing. The anti
msms.
eration of the manually operated mechanical parking
friction bearing 23‘ is secured within the brake housing
brake mechanism, a suitable valve being provided to cut
by means of the snap ring 54».
off or resist the circulation of cooling liquid to the brake
The brake disk carrier 17 supports a seal ring 25 that
and thereby effect delivery of the pressure liquid to the 60 has a seal member 26 engaging the annular wall 27 of the
wheel cylinder of the hydraulic brake and thereby hy
brake housing that prevents loss of coolant ?uid from
draulically effect engagement of the disks of the brake as
within the brake housing.
a power assist to the manually operated mechanical
Stationary brake disks 30 are positioned between the
mechanism, the valve being actuated by actuation of the
rotatable brake disks 22 and ‘are supported upon a plu
65
mechanical mechanism so that the hydraulic power assist
rality of studs 31 which prevent their rotation. Either
occurs only when the parking brake mechanism is actu
of the brake disks 3!) or 2.2 have friction tracings of any
ated.
conventional type which facings are provided with grooves
The power assist of the manually operated mechanism
to allow circulation of cooling oil between the disks when
also provides a more satisfactory operation of the park
the disks are in engagement with one another.
ing brake mechanism when used for emergency stopping 70
of the vehicle as the hydraulic power assist can be regu
The brake disk assembly, comprising brake disks 2.2
and 30 are brought into engagement with one another by
3,036,869
3
means of a pressure plate 32 that has an annular axial
extending portion 33 positioned within an annular groove
34 provided in the brake housing 15. The annulus 33
carries an annular ring 35 that is T-shaped in transverse
cross section, seal members 36 being provided between
the ring 35 and the annulus 33. The space 37 between
the bottom of the groove 34 and the ring 35 forms a
so that hydraulic liquid displaced by the master cylinder
70 will pass to the chamber 37 of the wheel cylinder and
thereby effect engagement of the brake disks 22 and 30.
A brake line 77 connected with the port 78 is adapted to
connect other brakes of the vehicle with the valve cham
ber 75 for concurrent actuation of the other brakes at
other wheels of the vehicle.
The valve chamber 75 contains a two-position valve
chamber to receive hydraulic ?uid under pressure from a
112 that ?ts on the inner end of the passage 75 and closes
master cylinder whereby to effect axial movement of the
member 35 and the pressure plate 32 to cause pressure 10 on a seat 111 against ?ow of hydraulic ?uid in a left hand
direction through the passage 74 but allows freedom of
engagement of the brake disks 22 and 30, Retraction
movement of the hydraulic ?uid from the brake line 72
springs 38 are placed around the studs 39 and positioned
into the valve chamber 75.
between the pressure plate 32 and the Wall of the housing
The same valve 112 seats on seat 110 and connects
15 to provide for dis-engagement of the brake disks when
15 the valve chamber 75 with the chamber 45 so that liquid
the brake pedal is released.
under pressure from the pump 40 can flow from the
To effect circulation of cooling liquid between the
chamber 45 into the valve chamber 75 and thence into
brake disks 22 and 30, a liquid pump 40‘ is carried on the
the passage 76 for delivery to the wheel cylinder chamber
spline 18 of the axle 11. In the drawing, the pump 40 is
of a conventional vane type that has a rotor 41 carrying
a plurality of radial vanes that engage the walls of the
pump cavity 42, the rings 43 retaining the vanes in en
gagement with the outer wall of the pump cavity. While
the pump 40 is speci?cally illustrated as being a vane
type pump, yet other positive displacement pumps, such
as a gear pump can be used.
The pump has its suction side connected with an inlet
line 62 that comes from an oil cooler, or heat exchange
37 in a manner hereinafter described.
The valve 112
prevents ?ow of hydraulic ?uid from the valve chamber
75 into the chamber 45 when hydraulic ?uid is being de
livered into the chamber 75 from the master cylinder 70.
Thus there are two sources of hydraulic pressure for
delivery to the wheel cylinder chamber 37, the ?rst being
25 the primary source from the master cylinder 70 and the
second being from the pump 40. In the event the brake
line 72 should break, ?uid under pressure can be de
‘livered from the pump 40 through the passage 82 and
into the chamber 75 and thence through passage 76 to
the wheel cylinder chamber 37 to effect hydraulic actua
device, the inlet line being connected with ‘a suction cham
ber 63 from which the pump receives its liquid.
The pump 40 discharges liquid under pressure into the
tion of the brakes as an emergency measure.
discharge passage 44 from which a liquid under pressure
To provide for delivery of ?uid under pressure from
?ows into a cylindrical chamber 45 and thence into a pas
the pump 40 into the wheel cylinder chamber 37 a valve
sage 46 that delivers the coolant liquid under pressure
member 90 comprising a piston slidable in the chamber
into the brake chamber 47. Coolant liquid ?ows be
tween the brake disks 22 and 30 into the chamber 47 and 35 45 is adapted to have one position illustrated in the draw
ing to close off passage 46, or at least resist flow of ?uid
exhausts through the outlet line 48 for return to the oil
from the pump exhaust passage 44'into the passage 46.
cooler or heat exchange device.
The valve piston 90 is adapted to be positioned in the po?
So long as the shaft 11 rotates, the positive displace
sition shown in the drawing by means of a link 91 con‘
ment pump 40 will effect circulation of cooling liquid
through the brake and between the brake and the heat 40 nected with the lever arm 50 of the manually operated
parking lever mechanism. This link 91 has a downwardly
exchange device.
extending projection 92 that engages a spring 93 retained
It is conventional to provide a parking lever mechanism
on a rod 94 that extends from the valve piston 90.
for actuating the brake in at least the rear Wheels of the
When the lever arm 50 is pivoted in a right hand direc-~
motor vehicle to retain the vehicle in a stationary position
when the parking brake has been set. In this invention ' tion about the stud 51, the extension 92 on the link 91 en
gages the spring 93 to prevent the piston valve 99 from
the parking or emergency lever mechanism consists of
moving in a left hand direction except against compres
a lever arm 50 that is pivoted on a stud 51. A pin 52
sion of the spring 93 so that liquid being discharged from
extends between the lever arm 50 and a slidable plug 53
the pump 40 will build up a su?icient pressure to exhaust
that engages the ring 35 of the wheel cylinder to actuate
the ring 35 when the lever arm 50 is pivoted on the 50 through the port 82 into the valve chamber 75 for de
livery into the wheel cylinder chamber 37. When the
stud 51.
parking lever mechanism, or emergency lever mechanism
The upper end of the lever arm 50 is engaged by a
is set in the position just described, hydraulic liquid under
cable 55 that extends from ‘a pull lever mechanism 56
pressure from the pump 40 will give a hydraulic power
to effect setting of the brake when the pull mechanism 56
assist to the action of the parking lever mechanism so that
is actuated.
manual actuation of the plunger 53 to effect engagement
The mechanism 56 may be of any conventional type
of the brake disks 22 and 30 will be concurrently assisted
and is illustrated as consisting of a ratchet 57 engaged
by the hydraulic actuation of the piston ring 35 of the
by a pawl 58 that prevents the ratchet 56 from moving
wheel cylinder.
in a left hand direction until the pawl 58 is rotated about
its pivot 59 by lifting the member 60. A stop pin 61 60 To prevent pressure from going beyond a predetermined
maximum value and thereby control the maximum hy
prevents clockwise rotation of the pawl 58. Thus when
draulic pressure to be applied from the pump 40 into the
the ratchet 57 is moved in a right hand direction the
wheel cylinder chamber 37, a pressure operated by-pass
lever arm 50 will be rotated in a clockwise direction about
valve 95 is provided between the passage 44 and the pas
the stud 51 to move the pin 52 in a left hand direction
sage 46 to by-pass the piston valve 90 when it is retained
and thereby effect engagement of the brake disks 22
in the position shown in the drawing.
and 30.
When the parking lever mechanism is in the position
A hydraulic actuating mechanism to effect engagement
illustrated in the drawing, the piston valve 90 can move
of the brake disks 22 and 30 consists of a conventional
freely in a left hand direction to open the passage 46 to
master cylinder 70 that is operated by a foot pedal 71.
Fluid displaced by the master cylinder 70 is discharged 70 the right hand end of the chamber 45 and thereby connect
it with the passage 44 for free circulation of liquid de
under pressure into the brake line 72 which enters a
livered by the pump 40 for cooling of the brakes in a
port 73 in the brake housing 15. The port 73 is con
nected with a passage 74 that in turn is connected with
a valve chamber 75. A passage 76 connects the valve
manner hereinbefore described.
While the form of embodiment of the invention as here
chamber 75 with the chamber 37 of the wheel cylinder 75 in disclosed constitutes a preferred form, it is to be un
3,036,889
derstood that other forms might be adopted as may come
within the scope of the claims which fol-low.
What is claimed is as follows:
1. A brake actuating system for the brakes of a wheeled
vehicle, comprising, friction brake means, ?rst hydraulic
means including wheel cylinder means actuating said
brakes connected through conduit means with a master
cylinder actuating said wheel cylinder means, second me
chanical means actuating said brake means independently
of said hydraulic means, pump means circulating cooling 10
liquid through said brake means, valve means actuated by
said mechanical means directing liquid flow from said
6
stricting such ‘?ow, said valve means being connected with
said mechanical means whereby to dispose said valve
means in its said second position on actuation of said me—
chanical means to apply said brake means, and second
valve means in said conduit means and providing com
munication between said master cylinder and said Wheel
cylinder in the ?rst position, a second position providing
communication between said ?rst valve means to provide
for delivery of liquid under pressure from said pump to
said wheel cylinder when said ?rst valve means is in its
said second position.
4. A brake actuating system for the brakes of a wheeled
pump means to said conduit means and said wheel cylin
vehicle, comprising, friction brake means, ?rst hydraulic
der means to actuate said brakes concurrently with actua
means including wheel cylinder means actuating said
tion by said mechanical means, and other valve means in 15 brakes connected through conduit means with a master
said conduit means closing off the conduit means to said
cylinder actuating said Wheel cylinder means, second
master cylinder when the liquid pressure in the wheel cyl
mechanical means actuating said brake means independ
inder from the pump is higher than the liquid pressure
in the master cylinder.
2. A brake actuating system for the brakes of a wheeled
ently of said hydraulic means, pump means circulating
cooling liqud through said brake means, valve means in
fluid flow circuit relationship between said pump means
vehicle, comprising, friction brake means, ?rst hydraulic
and said brake means having one position providing for
means including wheel cylinder means actuating said
?ow of liquid from the pump means to the brakev means
for cooling said brake means and a second position re
brakes connected through conduit means with a master
cylinder actuating said wheel cylinder means, second me
stricting such flow, said valve means being connected with
chanical means actuating said brake means independently 25 said mechanical means whereby to dispose said valve
of said hydraulic means, pump means circulating cooling
means in its said second position on actuation of said
liquid through said brake means, valve means actuated by
mechanical means to apply said brake means, second valve
said mechanical means directing iiquid flow from said
means in said conduit means and providing communication
pump means to said conduit means and said Wheel cyl
between said master cylinder and said wheel cylinder in the
inder means to actuate said brakes concurrently with ac
?rst position, a second position providing communication
tuation by said mechanical means, and other valve means
between said ?rst valve means to provide ‘for delivery of
in said conduit means providing ?rst for cutting off flow
liquid under pressure from said pump to said wheel
of liquid from the pump means to the wheel cylinder so
cylinder when said ?rst valve means is in its said second
long as pressure in the conduit means between the master
position, and additional valve means in by-pass relation to
cylinder and the Wheel cylinder is above the pressure in 35 said ?rst valve means providing for ?ow of liquid from
the outlet side of the pump means and second for closing
said pump to said brake means when pressure in the out
off the conduit means to said master cylinder when the
let side of the pump reaches a predetermined value with
liquid pressure in the wheel cylinder from the pump is
the said ?rst valve means in its second position whereby to
higher than the liquid pressure in the conduit means be
limit liquid pressure applied to said wheel cylinder from
tween the master cylinder and the said other valve means. 40 said pump.
3. A brake actuating system for the brakes of a wheeled
vehicle, comprising, friction brake means, ?rst hydraulic
References Cited in the ?le of this patent
means including wheel cylinder means actuating said
UNITED STATES PATENTS
brakes connected through conduit means with a master
cylinder actuating said wheel cylinder means, second 45
mechanical means actuating said brake means independ
ently of said hydraulic means, pump means circulating
cooling liquid through said brake means, valve means in
?uid flow circuit relationship between said pump means
and said brake means having one position providing for 50
?ow of liquid from the pump means to the brake means
for cooling said brake means and a second position re
1,883,588
2,226,457
Crane ________________ __ Oct. 18, 1932
Whittingham __________ __ Dec. 24, 1940
2,406,304
2,788,870
Levy ________________ __ Aug. 20, 1946
Heck ________________ __ Apr. 16, 1957
35,108
Denmark ____________ __ Sept. 24, 1925
505,513
France ________________ __ May 7.1920
FOREIGN PATENTS
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